Retrospective comparison of autologous bone grafting and vascularized pedicled pronator quadratus muscle flap in the management of scaphoid nonunions

Aim: In the cases of scaphoid nonunion, although there is a consensus about the necessity of surgical treatment, different treatment modalities are available. In the literature, a large number of studies, which have reported favorable outcomes with autologous bone grafting, vascular grafting, and others, have been reported, are present. We aimed to compare the clinical outcomes of two surgical treatment techniques, the vascularized pronator quadratus pedicled muscle graft, and autologous bone graft in the management of scaphoid nonunions. Patients and Methods: 50 patients who were diagnosed and treated due to scaphoid nonunions between 2009 and 2017 at the İstanbul University, İstanbul Faculty of Medicine were retrospectively reviewed. Patients who had a history of previous surgery with the wrist, wrist instability, or wrist osteoarthrosis were excluded, a total of 39 patients operated by the same surgical team were enrolled in the present study. All the patients were male. Of 39 patients, 24 underwent the autologous bone graft, and 15 were operated using the vascularized pronator quadratus pedicled muscle graft. The time from the fracture to surgery ranged from 11 months to 80 months. The mean length of the follow-up was months with a range of 9 months to 108 months. Results: Of all the patients, 33 (%84,6) showed osseous union, 6 (%15,4) were complicated by nonunion. While the osseous union was obtained in 19 patients from the group of autologous bone grafting with the union rate of 79%, the osseous union was achieved in 14 patients from the group of the vascularized pronator quadratus pedicled muscle graft with the union rate of 93%. The mean time to union was 12,48 ± 1,62 months ranging from 8 to 16 weeks. The mean time to union was 12, 79 weeks in the group of autologous bone graft and 12,07 weeks in the group of the vascularized pronator quadratus pedicled muscle graft. Between two groups, the dominant side, fracture configuration, the presence of avascular necrosis, and the mean age were comparable. No significant difference was observed between two groups in terms of union rate, time to union, and time from the fracture to surgery (p>0,05). Furthermore, there was no statistically significant difference in terms of The Mayo wrist score, and VAS score (p>0,05). Similarly, scapholunate angle measurements and Nattrass carpal height showed no significant difference between two groups pre- and ameliyat sonrasıeratively (p>0,05). Between both groups, no statistically significant differences were found in key pinch strength, postoperative flexion, and ulnar deviation measurements (p>0,05). Moreover, there was no significant difference in union status and time to union among proximal part fractures (p>0,05). Union rates show no statistical difference far patiens with avasculer necrosis (20) compared to other groups. Postoperative extension degrees and radial deviation measurements are greater in the group of autologous bone graft than in the group of the vascularized pronator quadratus pedicled muscle graft (p=0,011; p<0,05 for extension measurement, p=0,003; p<0,01 for radial deviation). Conclusion Vascularized pronator quadratus pedicled muscle grafting technique can be preferred for scaphoid nonunion treatment in avasculer necrosis patients, in proximal scaphoid fractures and in cases which could not be treated succesfully with other methods due to its relatively undemanding surgical technique, fewer complications, higher union rates and higher patients satisfaction.